This disclosure relates generally to graphene-based composite materials, and more particularly, to reduced graphene oxide composite materials and their methods of manufacture. This disclosure also relates to the application of the composite materials in electronic devices.
Polymeric materials have great potential for application in electric capacitors, piezoelectric devices, optical modulators, storage media, memory devices, and the like. Unfortunately, the dielectric permittivity of polymer materials is typically less than desirable; and in order to realize the potentials of polymer materials, it is necessary to substantially improve their dielectric permittivity.
One way to improve the dielectric permittivity of polymer materials is to introduce ceramics of high dielectric permittivity as fillers into the polymer matrix of the polymer materials. However, the improvement on dielectric permittivity is limited even with high filler loadings. In addition, the mechanical properties of the polymer materials such as flexibility can be compromised with the use of ceramic fillers.
Incorporation of conductive metal nanoparticles such as Ag, Al, Ni, Cu, or Au, conductive polymers such as polyaniline, and oligomers such as copper phthalocyanine in polymer materials results in composites having a range of dielectric permittivity. The major drawback of such composite systems is that the dielectric losses also significantly increase due to insulator-conductor transition near the percolation threshold. The significant dielectric losses limit the use of such composite materials in practical applications. Additionally, the improvement of dielectric permittivity of the reported systems sometimes is still less than desirable. Accordingly, there remains a need for composite materials having high dielectric permittivity and low dielectric losses at the same time.